The present disclosure generally relates to pneumatic compressors, and more particularly relates to an oil-free air compressor used for supplying compressed air to a pneumatic tool.
Conventional air-cooled compressors have an open frame structure for supporting a cylinder having a compression chamber, and for providing the mounting point for other compressor components. The cylinder typically has a mounting flange on its upper end adjacent a valve plate, and is commonly made of cast aluminum or steel. During compressor assembly, the cylinder is inserted into, and held by a port in the frame structure. Specifically, the cylinder flange is axially confined from below by an annular region around the port, and from above by the valve plate and a valve plate sealing gasket.
In operation, gases are rapidly heated in the cylinder. To improve efficiency of the compressor, and protect associated components, most conventional compressors use cooling air or liquid to remove thermal energy from the cylinder. Effective cooling of the cylinder is important because the cylinder is a significant part of the compression cavity. Typically, the highest temperature of the cylinder is measured at the top of the cylinder close to the valve plate, because a pressure of the gas is higher at the top than the pressure at the bottom. Thus, the top portion of the cylinder is the most important region to cool.
However, the frame structure of conventional compressors restricts the flow of cooling air or liquid to the top portion or region of the cylinder, thereby causing the temperature of the cylinder to rise significantly during operation, reducing the operational life of certain components, and in some cases damaging the cylinder and adjacent components. Thus, there is a need for developing an improved frame structure for cooling the top region of the cylinder during a compression process.